I'm not sure how Forge handles the relation between block side and inventory slots, but I would like to auto-refill my Writing Desk, that is, insert paper and ink vials and retrieve empty vials. However, it doesn't matter what side (of the 10 available, two blocks wide), I can only insert the paper. I would like to know what is the side connected to the ink vials inventory slot for this block, and also, if possible, how can I easily determine that for any given block. Finally if there is no association, is there any other way to auto refill my desk?
The Mystcraft Writing does does implement ISidedInventory, but the only slot that is bound to anything is the paper slot, you may be able to use factorization routers to insert/extract bottles.